Data from: Ecdysteroid hormones link the juvenile environment to alternative adult life histories in a seasonal insect

The conditional expression of alternative life strategies is a widespread feature of animal life, and a pivotal adaptation to life in seasonal environments. To optimally match suites of traits to seasonally changing ecological opportunities, animals living in seasonal environments need mechanisms linking information on environmental quality to resource allocation decisions. The butterfly Bicyclus anynana expresses alternative adult life histories in the alternating wet and dry seasons of its habitat, as end points of divergent developmental pathways triggered by seasonal variation in pre-adult temperature. Pupal ecdysteroid hormone titers are correlated with the seasonal environment, but whether they play a functional role in coordinating the coupling of adult traits in the alternative life histories is unknown. Here, we show that manipulating pupal ecdysteroid levels is sufficient to mimic in direction and magnitude the shifts in adult reproductive resource allocation normally induced by seasonal temperature. Crucially, this allocation shift is accompanied by changes in ecologically relevant traits, including timing of reproduction, lifespan and starvation resistance. Together, our results support a functional role for ecdysteroids during development in mediating strategic reproductive investment decisions in response to predictive indicators of environmental quality. This study provides a physiological mechanism for adaptive developmental plasticity, allowing organisms to cope with variable environments. 25 pages, 4 figures; Appendix

备选生活策略的条件性表达是动物生命活动中普遍存在的特征，亦是生物适应季节性环境的关键适应性策略。为使性状组合最优匹配季节性变化的生态机遇，栖息于季节性环境中的动物需构建将环境质量信息与资源分配决策相联系的调控机制。眼蝶（Bicyclus anynana）在其栖息地干湿季交替的环境中，会呈现两种截然不同的成虫生活史，这两类表型均为成虫前期温度季节性变化所触发的分化发育通路的终末产物。蛹期蜕皮甾体激素滴度与季节性环境存在相关性，但目前尚不明确其是否在协调备选生活史中成虫性状的耦合关系中发挥功能性作用。本研究证实，操控蛹期蜕皮甾体激素水平，足以在方向与幅度上模拟由季节性温度通常诱导的成虫繁殖资源分配变化。至关重要的是，此类资源分配转变同时伴随一系列生态相关性状的改变，包括繁殖起始时间、寿命及饥饿抵抗能力。综上，本研究结果支持蜕皮甾体在发育过程中，可通过介导针对环境质量预测指标的战略性繁殖投入决策发挥功能性作用。该研究为适应性发育可塑性提供了一套生理学机制，助力生物体应对多变的环境。全文共25页，附图4幅；含附录